Mildew resistant organopolysiloxane with hydrolyzable organosilane and triazolyl compound

Abstract

A room temperature curable mildew resistant organopolysiloxane composition comprises (A) a hydroxyl or hydrolyzable group-containing organopolysiloxane, (B) a hydrolyzable organosilane such as methyltrimethoxysilane, methyltris(methylethylketoxime silane) or vinyltris(methylethylketoxime silane), a partially hydrolyzed product thereof or a mixture of the hydrolyzable organosilane with the partially hydrolyzed product thereof; and (C) a triazolyl group-containing compound such as 2-(4-chlorophenyl)ethyl-α-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-yl-ethanol. Preferably, the component (B) does not contain aliphatic unsaturation in the molecule, and in this case, the component (B) free of aliphatic unsaturation is used in combination with (B') a hydrolyzable silane such as tetrakis(dimethylketoxime)silane, a partially hydrolyzed product thereof or a mixture of the hydrolyzable silane and the partially hydrolyzed product thereof.

What is claimed is: 
     
       1. A room temperature curable mildew resistant organopolysiloxane composition, comprising (A) a fluid hydroxyl or hydrolyzable group-containing organopolysiloxane represented by the following general formula (1): ##STR12## wherein X is a hydroxyl group or a hydrolyzable group, a plurality of R 1 , which may be the same or different, are independently a monovalent hydrocarbon group, n is an integer of 8 or more, so that the organopolysiloxane has a viscosity at 25° C. of from 25 to 500,000 cSt and a is an integer of 1 to 3;   (B) from 0.1 to 30 parts by weight per 100 parts by weight of (A) of at least one compound selected from the group consisting of a hydrolyzable organosilane represented by the following general formula (2-b):   R.sup.8.sub.e Si(ON═CR.sup.9.sub.2).sub.(4-e)          ( 2-b)     wherein R 8  is an unsubstituted or substituted monovalent saturated aliphatic hydrocarbon group, R 9  is an unsubstituted or substituted monovalent hydrocarbon group, and e is an integer of 1 to 2; and a partially hydrolyzed product thereof;     (B') from 0.1 to 10 parts by weight per 100 parts by weight of (A) of at least one compound selected from the group consisting of a hydrolyzable silane represented by the following general formula (2-b'):   Si(ON═CR.sup.9.sub.2).sub.4                            ( 2-b')     wherein R 9  is an unsubstituted or substituted monovalent hydrocarbon group, and a partially hydrolyzed product thereof; and     (C) from 0.1 to 5 parts by weight per 100 parts by weight of (A) of a triazolyl group-containing compound represented by the following general formula (3):   Y--CR.sup.3 R.sup.4 --CR.sup.5 R.sup.6 --Z                 (3)     wherein R 3  and R 4  are independently a hydrogen atom or an unsubstituted or substituted monovalent hydrocarbon group, R 5  and R 6  are independently a hydrogen atom, an alkyl group or an alkoxyl group, Y is a hydroxyl group or a nitrile group, and z is a triazolyl group.     
     
     
       2. The composition according to claim 1, wherein in said general formula (1), R 1  is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms. 
     
     
       3. The composition according to claim 1, wherein in said general formula (1), R 1  is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms and containing no aliphatic unsaturation. 
     
     
       4. The composition according to claim 1, wherein in said general formula (1), each of the hydrolyzable group X is selected from the group consisting of alkoxy, ketoxime, acyloxy, amino, amido, aminoxy and alkenyloxy groups. 
     
     
       5. The composition according to claim 1, wherein the component (A) is a silanol group-containing organopolysiloxane represented by the following general formula (1-a):   HO(SiR.sup.1.sub.2 O).sub.p H                              (1-a)     wherein R 1  is as defined in claim 1, and p is an integer of 10 or more so that the organopolysiloxane has a viscosity at 25° C. of 25 to 500,000 cSt.   
     
     
       6. The composition according to claim 1, wherein the component (A) is a hydrolyzable group-containing organopolysiloxane represented by the following general formula (1-b): ##STR13## wherein a plurality of R 7  are an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, a plurality of X' are a hydrolyzable group, c is an integer of from 2 to 3 on average, and m is an integer of 10 or more so that the organopolysiloxane has a viscosity at 25° C. of 25 to 500,000 cSt. 
     
     
       7. The composition according to claim 6, wherein the hydrolyzable group-containing organopolysiloxane of the component (A) represented by the general formula (1-b) is present in combination with the triazolyl group-containing compound, as the component (C), in which the triazolyl group Z in said general formula (3) is a 1,2,4-triazole-1-yl group represented by the following formula (3-a): ##STR14## 
     
     
       8. The composition according to claim 7, wherein said triazolyl group-containing compound of the component (C) is 2-(4-chlorophenyl)ethyl-α-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-yl-ethanol. 
     
     
       9. The composition according to claim 1, wherein the components (B) and (B') as defined in claim 1 are present in combination with a triazolyl group-containing compound, as the component (C), represented by the formula (3-a) as defined in claim 7. 
     
     
       10. The composition according to claim 9, wherein said triazolyl group-containing compound of the component (C) is 2-(4-chlorophenyl)ethyl-α-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-yl-ethanol.